Theodore of Mopsuestia

It says “The Lord is in his holy temple,” as if it had been appropriate to say “The Lord is his help.” For the Lord’s name alone is commonly inserted as an indication of assistance. But here the psalmist intends to indicate that there is one who lives in the temple and is used for defense and protection, in whom it is able to stand firm securely in hope against all treachery. But what it calls the temple is the tabernacle in which the ark of God was placed, for the temple had not yet been built. That the tabernacle may be called the temple, the testimony of Kings [Samuel] clearly instructs, since the construction of the temple had not begun at the time: “And Samuel was lying down in the temple of God, in which the ark of God was located.”